


Born Under a Bad Sign

by Tainted_Grace



Category: Teen Wolf (TV)
Genre: Alpha Derek Hale, Bottom Stiles Stilinski, Derek and Stiles are Mates, Established Derek Hale/Stiles Stilinski, Full Moon, Knotting, M/M, PWP, Shameless Smut, Sorry Not Sorry, Top Derek, True Alpha Scott McCall, Werewolf, i have no idea how to tag right, request, stiles has a knotting kink
Language: English
Status: Completed
Published: 2015-05-10
Updated: 2015-05-10
Packaged: 2018-03-29 20:22:11
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,036
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3909376
Author URL: https://archiveofourown.org/users/Tainted_Grace/pseuds/Tainted_Grace
Summary: <blockquote class="userstuff">
              <p>Stiles and Derek have been unofficially dating for almost five months but Stiles has never seen Derek on a full moon since they got together. When Derek catches Stiles doing something... interesting, it gives Stiles the perfect opportunity to ask for what he wants. And what he wants is Derek. Wolfed out. On a full moon.</p><p>Warning: Contains knotting</p><p>This is a request for the lovely Mulder200. Thanks for the amazing idea! This is easily the dirtiest thing I have ever written, ever. Thanks so much for the opportunity!</p>
            </blockquote>





	Born Under a Bad Sign

**Author's Note:**

  * For [Mulder200](https://archiveofourown.org/users/Mulder200/gifts).



> I am so sorry if I completely ran wild with your prompt, it just sort of happened and I had to add an agitated Scott in there, if only a little bit. Thanks, and if you don't like it let me know and I can always write it over.
> 
> This is easily the dirtiest thing I have ever written, ever. Thanks so much for the opportunity!

Stiles and Derek have been unofficially dating for almost five months, and Stiles has yet to spend the night with Derek on a full moon. If he’s being fully honest here, the thought of being there when Derek lets his dark side out, when he lets his carefully cultivated control slip, if even just a little, turns him on more than it really should. The thought of Derek fully wolfed out with razor sharp claws, glowing red eyes, pointed ears with supersonic hearing, and fangs that could probably tear through a tank, should terrify him beyond all belief, but Stiles can’t help but imagine how the _sex_ would be on that one particular night.

Derek is absolutely mind blowing in bed on a normal night when he is being a perfect gentleman and has all of the self-control in the world, but Stiles wants to know the Alpha’s darker side, his more animal side. He has never brought it up to his lover though, because he knows the man would never, ever agree to it. So Stiles resigns himself to jerking off in his Jeep on the side of an abandoned part of Highway 35 just south of the remains of Derek’s family’s burnt down house where he knows Derek is reinforcing the basement to hold him in in just two nights.

Stiles sighs in pleasure when he wraps his hand around his beet red cock, twisting his fist just under the head and moaning in sweet agony at the rush of pleasure that steals the air from his lungs. The hand that isn’t tugging on his dick slips lower to fondle his balls, his eyes squeezed shut as he imagines Derek doing those things to him as a promise as the sun sinks lower into the sky and the moon rises to replace the bright ball of light. Stiles kicks his shoes off and then his jeans and boxer-briefs before flipping into the backseat and reaching under the seat for his box of toys.

He pulls out one of his favorite toys, a bright pink dildo that he convinced Derek to buy on a dare from the shady sex shop two towns over a few weeks back. The rubber dick is at least eight inches long and almost as thick as Stiles’ wrist. He pulls out the tube of chocolate flavored lube that Danny got him for his last birthday as a joke but that has been damn helpful lately and slicks up three of his fingers before sitting the tube in the cup holder under the window by his face. He wastes no time in prepping himself with the fingers, moaning as he adds each one and imagines its Derek instead. He can almost imagine that the Alpha’s thick fingers are pushing inside of him instead of his long, thin fingers, but he still wishes it was the real thing.

“Holy shit, Der.” He hisses under his breath when his fingers brush over his prostate and send a wave of arousal shooting straight through his veins like fire.

He doesn’t stop at just fingers, his research having made him curious enough to do more than that. He lubes up the alarmingly pink dildo and sits in the center of the bench, his forearm hooked over the front seat to hold him in place as he sinks down onto the toy. He nearly screams as the rubber dick rubs across his prostate but he bites it back and reaches back behind himself to finger at his hole around the monster cock that is bigger than anyone he has even seen, well, anyone but Derek, that is.

He yelps slightly when he tries to slide a finger in beside the toy, breathing hard and pushing himself up slightly. When he drops back down onto the fake cock he manages to fit his finger in beside and the sensation nearly has him crying out and coming at the same time. Stiles knows if he wants to ever be with Derek on a full moon, he needs to be able to do this, to be able to take something twice the size (or more) of his boyfriend’s cock. After about twenty minutes of massaging and rocking against the pink dick, Stiles manages to slip all of his fingers in beside the toy. The angle is weird and it sorta hurts his wrist, but he still moans at the feeling rushing through his body.

When it becomes almost easy to push his entire fist inside along with the toy he reaches back inside the box and pulls out a slightly smaller, slightly less neon blue dildo with a remote rubber banded to the tip. Stiles slips his fingers out of his hole with a sigh, taking off the remote and rubber band before slicking up the blue dildo and sliding off of the pink one already in his ass. When he pushes back down he pushes both toys inside his tight hole, letting out a low whimper that builds and builds to a scream that echoes around the inside of his jeep as he sits fully on the two rubber cocks in his ass. His eyes are watering and his muscles are strung tighter than bowstrings, but his cock is still as hard as a diamond between his thighs.

Stiles reaches for the remote with a shaky hand, unsure if he can last much longer with the constant press on his prostate that sends electric shocks through his nerves every time he shifts. He presses a red button on the small rectangle and then he’s screaming even louder than before, all pain being lost as the vibrations coming from the toy attack his prostate and toss him over the edge of his orgasm. He pants and sighs as he comes down from his high, eyes blurry and body flushed bright red as his cock twitches, spilling even more cum onto the back of his front seat.

A small part of his brain remembers that most of the people that sit in the Jeep are going to be able to smell the release, but the thought quickly disappears when his door is yanked open a head of dark hair is peeking inside, only to freeze as the scent of arousal and release attack his sensitive nose. Derek’s eyes flash bright red and then return to green, pupils dilating to the point where the emerald is nothing more than a thin ring around the edge of his irises. Derek looks ready to pounce on the teen until he climbs into the seat and shuts the door, seeing the bottle of lube open in the window, the box of toys on the seat beside his boyfriend, the jeans and boxers tossed carelessly in the passenger seat in the younger man’s haste, and then it registers that Stiles looks completely fucked in the back seat of his car.

“Stiles…” Derek says evenly, trying to keep his control despite the wolf inside him growling at him to _claim_ and _mark_ and _take_ and _feel_ , _now, now, now._ “What the hell are you doing?”

“I missed you.” Stiles shrugs, panting and moaning brokenly when he shifts slightly and the still vibrating toy bounces off his oversensitive prostate again.

“What the-?” Derek gulps when he looks closer and sees the blue and pink disappearing inside Stiles’ ass. “Did you-? Stiles, is that _two_ of our toys?”

“Mm-hm. _AH!_ So good, Der. Not as good as you, but, _ungh_ , wanted to feel it.” Stiles explains, rocking on the toys as his cock starts to fill again just from the sensations on his prostate and that look in Derek’s eyes that screams _fuck me._

“Feel what?” Derek nearly drools at the sight of the toys vanishing into the tight channel that he knows is warm and as smooth as velvet.

“Ngh! Y-Your kn-knot. I k-knew you would nev-never say yes, so, _AH_ , I improvised.” Stiles arches his back at the constant pressure on the most sensitive part of his anatomy and Derek is nearly shaking with his effort to stay in his place and not take Stiles right there in that backseat in that Jeep that he has offered to replace at least a dozen times.

“My kn- Stiles, you want me t-?” Derek looks thoroughly floored by the realization and Stiles nods frantically as he nears his second orgasm of the past hour.

“Wanna feel you, Der. All of you. Even the animal part.” He groans with his head tossed back so far that Derek thinks it might snap at any second.

“Are you sure? It’s a knot, Stiles.” Derek argues and Stiles bites his lip, nodding his head, well, more like twitching it back and forth quickly.

“It’s you, Derek. _Holy_ \- I’m sure, baby. I wanna see you. All of you.” Stiles pants, rocking frantically on the toys pushing in and out of his body.

Derek groans and motions for Stiles to turn around and show him. Stiles moans and proudly flips onto his knees and braces himself on the back of the seat to show off what he has been doing. Derek nearly growls and shifts at the sight of Stiles stretched and twitching around the rubber cocks in his ass. Derek can hear the blue one vibrating against the male’s skin, can hear the filthy squelching of lube shifting between the two toys as Stiles tries to pull them even deeper inside his body. “Derek, please!” He begs helplessly and Derek does growl, hand twitching forward and pushing the toys further inside his boyfriend’s ass and watching the way his body reacts. His back bends and his head falls onto Derek’s shoulder as his hips buck against the seat and try to find enough friction to make him come.

“Stiles, let go. Come for me baby. Show me how good you are.” Derek orders and Stiles screams again, his cock twitching with his release as he spills onto the opposite side of the seat as the first time.

“I can’t- Der, please, t-take them out.” Stiles begs and Derek pulls the toys out without even thinking about trying to make Stiles come again.

“You really want me to knot you, babe?” Derek asks as he’s helping Stiles back into his boxers and pants.

“Uh, yeah. I do. You never let me see you on a full moon, Derek. I know you aren’t gonna hurt me.” Stiles blushes, trying to prove his point without making Derek say flat out ‘no.’

“If you’re sure, then be at the loft at sunset. But if you aren’t 100% sure, do _not_ show up, Stiles. I need you to be confident so I can stay in control and not rip you to shreds.” Derek sighs, knowing that if he doesn’t agree now Stiles will resort to tricking him into saying yes anyway.

\---

When the night of the full moon comes around Stiles drives over to Derek’s loft in the warehouse district of town. Every five seconds Stiles shifts in his seat, the giant plug Derek bought yesterday glancing off his prostate with every twitch and bump of the Jeep. Stiles makes it up the stairs and into the loft just as the sun disappears over the far horizon. Derek comes down the stairs in the corner and meets him half way. The werewolf pulls his boyfriend into a tight hug that could probably crush Stiles’ ribs if Derek tightened his arms just a little bit more.

“There’s something I didn’t tell you about what you want.” Derek admits sheepishly, his cheeks a light shade of pink that Stiles has never seen before.

“Yeah? And what’s that?” Stiles hums against Derek’s overly built chest with a smile on his face.

“Alphas… we only ever knot one person in our entire lives.” Derek says and Stiles rolls his eyes, calming down when he realizes what Derek means.

“I know.” Stiles nods with a knowing glint in his honey-whiskey eyes.

“You know?” Derek asks in disbelief.

“Yeah, Alphas only ever knot their mate. I did research every single aspect of pack dynamics and lycanism like a year ago, Derek.” Stiles smirks with a scoff. “I know more about your shift than you probably do.”

“Oh really? How so?” Derek asks in disbelief, not thinking that Stiles could know half of what happens to him on a full moon.

“Well, you know I know all about what physically happens to you, your fangs and claws and all, but I also know that you see the world in shades of red as a wolf and that you lose most of your self-control when the moon hits its apex at roughly midnight. I know all about this, Der. I know all about you.” Stiles says surely, confident that he is actually not a dumb, ignorant human for once.

“You never cease to amaze me, Stiles.” Derek smiles, eyes lighting up slightly. The expression vanishes as his face goes serious and he looks deep into Stiles’ eyes, no doubt listening to his heartbeat as well. “Are you sure?”

Stiles nods, knowing that Derek needs to hear the words before he will feel even remotely okay with what they are about to do. “Yeah, I’m positive. I want to do this, Derek.”

The Alpha sighs and glances at the moon slowly rising into the sky before his eyes settle back on Stiles’ pale face covered in small brown moles that Derek has spent hours kissing and licking and memorizing. “Did you use it?”

“Why don’t you find out for yourself, Hale?” Stiles challenges and Derek groans as he pulls Stiles close to his chest and kisses the air from his lungs.

“Don’t challenge me, Stiles. Not tonight.” Derek begs and Stiles nods against the taller man’s forehead as he leads them to the bed under the window.

He pulls Derek’s skin tight wife beater over his head and sighs at the sight of his god-like abs and well defined pecs. He decides to take the moment to push his hands all over the planes and ridges of that torso while Derek pants and moans and bites at his lip until it looks ready to bleed. Stiles pulls off his own shirt as the moon climbs higher into the sky and Derek groans at the sight of even more moles dotting that flat torso with the beginnings of a six pack just starting to form. His fingers are tracing the small dots before he even realizes he’s doing it. Stiles lets him trace all over his skin, sighing out happily at the feeling of Derek’s sure fingers moving over his sensitive flesh.

“Are you sure?” Derek whispers again, hands resting on Stiles’ hips as the moon rises dangerously high in the night sky.

“Yes. I’m sure.” Stiles says, not an ounce of sarcasm in his voice. Derek huffs out a breath and then pops Stiles’ jeans open, sliding the zip down and then pushing the denim off of the younger’s body slowly, despite his control slipping with every second.

“Take them off.” Derek orders, snapping the band of Stiles’ boxers as he reaches for his own pants and pushes them off with his own boxer-briefs.

Stiles turns around so his ass in in Derek’s line of sight when he bends over and peels his underwear off. Derek growls at the sight of the black plug sitting snug against Stiles’ ass, stretching that ring of muscle that is red and puffy and gorgeous. Derek’s eyes go red and for once he lets them stay that way instead of forcing them back to green. As the moon crests in the sky Stiles crawls up the bed on his hands and knees, looking like the perfect prey, and when he gets to the head of the bed he reaches back and pulls the plug out of his hole with a quiet moan that causes Derek to start moving as he follows his boyfriend onto the bed.

Derek can feel his fangs drop and his ears lengthen and shift slightly as his face shifts slightly and his nails become deadly claws that he digs into his palms to stop himself from clawing at that pale spine right _there_ , right in front of him. Stiles rolls onto his back and scoots himself under Derek’s body, knowing that he has to do most of the moving until Derek gets inside him. Derek growls when Stiles reaches up for his head but Stiles just rests his hands on either side of his own head and bares his neck. Derek whimpers and noses at the expanse of skin, nipping and licking at the flesh without breaking the skin even though Stiles knows he so desperately wants to sink his teeth into the spot and claim what is already his.

“Stiles.” Derek says it like a prayer and Stiles sighs, trying once more to put his hands on Derek’s shoulders. He succeeds and smiles, slowly leaning up to kiss at the wolf’s jaw and making his way closer and closer to his lips, to those deadly canines that can tear through flesh as easily as butter.

“I’m here baby. I’m yours.” He says calmly, voice low and smooth as he kisses at the edges of Derek’s lips.

The Alpha huffs and presses his lips to Stiles’ greedily, wanting nothing more than to do anything Stiles asks him to for the rest of their lives. Stiles wraps his legs around Derek’s hips and moans when Derek thrusts against his thigh in response. His thrusts are slightly sloppy and uncoordinated but Stiles wouldn’t ask for it any other way. When he looks into those ruby red eyes and sees the ivory glint of fangs jutting from his boyfriend’s, his _mate’s_ , lips, it makes him feel safe and protected and loved. He reaches between them and grips the base of Derek’s cock, lining the thick organ up with his hole and looking deep into the werewolf’s eyes to the human beneath, to the man that Stiles both can’t stand and can’t stand to be without.

Derek does the rest, thrusting hard into the tight cavern and howling lowly into the crook of Stiles’ neck. Stiles knew Derek would be protective, but he had no idea that he would be this needy, this insecure. It somehow makes this even more intimate and Stiles grows bolder by the second as he learns what he can and cannot do to Derek when his control is hanging by a spider’s thread like this. Derek slides back out and slams back in hard enough to push Stiles up the bed and the human clings to his mate even tighter, eyes rolling into the back of his head as he feels that amazing dick press against his prostate on almost every thrust.

Derek’s hands, which were still balled into tight fists on either side of Stiles’ head, slowly find their way to Stiles’ hips, supporting his body with the tips of the nails just slightly digging into the skin, though not breaking the skin. Derek continues to fuck into Stiles’ body, eyes rolling into the back of his head as he feels his orgasm rise in his spine. Stiles grips his cock tightly in his fist, trying to not cum right then like he was 14 all over again and just learning what he could do with his dick. Stiles yelps when he feels something _big_ push at his rim, not having expected Derek to lose himself so soon, though in hindsight he guesses he should’ve at least assumed it would happen that way. He moans and Derek growls low in his throat, his grip on Stiles tightening as he tries to push the knot past Stiles’ tight rim.

When he finally succeeds in getting the knot inside he howls slightly louder, fingers tightening even farther and drawing blood from Stiles’ sinfully twisting hips on accident. The more he pushes, the bigger the thing grows until all he can do rock into the tight, hot space as Stiles moans and whimpers and tosses his head back and forth. The second Derek hits his prostate and doesn’t stop, Stiles is coming hard and fast, thick, white ropes of cum painting both of their stomachs as he pants and bucks up against his Alpha shamelessly.

Derek pushes even further into Stiles and holds himself there, feeling Stiles constrict around him being the final push he needs to go over the edge himself. He feels the knot grow to its full size and then he’s coming, pushing thick ropes of cum into Stiles’ ass and trapping it there. He whimpers and licks at the thin sheen of sweat covering Stiles’ shoulders and throat. His fangs still itch to dig into that pale neck reflecting the light of the moon and looking utterly perfect. He bets Stiles could survive the bite, wants to try, even, but he would never do that unless Stiles asked him to.

He huffs and settles against Stiles’ chest, his knees going numb the longer he kneels above the boy, waiting for the knot to go down. Stiles looks ready to pass out but he stays awake and runs a soothing hand through Derek’s hair to keep him calm as the moon sinks from the sky slowly. As the sun rises Derek slips out of Stiles’ body and curls the younger male into his chest protectively, his completely human teeth dragging over that spot that he so desperately wants to mark. “You could do it, y’know.” Stiles whispers softly, eyes trained on the sunrise outside the window.

“Hm?” Derek hums, hand stroking Stiles side, careful of the claw marks on his hip that he will have to apologize for later.

“Bite me. I know you want to. You’re practically buzzing with it. If you want to, do it, next time. But right now, go to sleep. And then we’re gonna take a bath because you are an _animal_ on the full moon and that actually made me a little sore.” Stiles grins with a wink and Derek chuckles, kissing his mate’s nose lovingly and snuggling further into his neck.

“Hey, Derek, have you seen…” Scott starts as he’s sliding the door open, his sentence trailing off when he sees Stiles wrapped up in Derek’s arms and smells the overwhelming _stench_ of sex that hits him like a brick wall. “Stiles.”

“Yeah, he’s right here. Why?” Derek groans in frustration, upset that the True Alpha decided to interrupt his cuddle time with Stiles.

“Oh come _on_! First Isaac sleeps with Allison and then you sleep with Derek!? _Why_ do you guys have a death wish?” Scott asks with a scowl on his face and a hand squeezing his nose shut against the smells assaulting his senses.

“What the hell are you talking about, man?” Stiles asks, his voice sex-drenched and tired but still full of sass, per usual.

“I went to check on Isaac last night and he was literally fucking Allison into the mattress. Then I come to see if Derek knows where you are and get assaulted by the worst smells ever. I didn’t not need to ever smell that, Stiles.” Scott complains and Stiles throws the closest thing to him at the Alpha, which happens to be Derek’s steel-toed work boot.

“Then get the fuck out! I didn’t ask you to check on me. I’ll see you later, or not. Just go before I throw the other shoe at you.” Stiles growls and Scott backs out of the loft at the pissed off tone in his sarcastic voice.

“That was a little harsh, don’t you think?” Derek asks when he pulls Stiles back into his chest again.

“Nope, I don’t think so. It’s his fault for being so protective and nosey in the first place. It serves him right. Now, shut up and cuddle me, Big Bad Wolf. I’m going through Derek withdrawals.” Stiles whimpers and Derek laughs against the teen’s back before kissing at the junction of his shoulder and throat.

“Says the kid who just got _knotted_ by said man. You’ll be fine.” Derek assures, rubbing Stiles’ side until he falls asleep and then following him into the dark abyss of unconsciousness.

 

**Author's Note:**

> Dont forget, you can find me on Tumblr at sterekinatrenchcoat (NOT stilesinatrenchcoat) and feel free to request a fic in my messages there, or in the comments here!
> 
> On a scale of Gerard Argent to Sterek Haleinski, how was this fic?


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